The problem with clicking someplace outside the window you are working on is that you will change focus, so any <Enter> or <Return> at that point wouldn't happen in the correct window, at least not with only a few lines of script.

I use mouse rocker combinations (hold down one button and click/doubleclick/triple click the other, hold down one button and click the scroll wheel, hold down one button and roll the scroll wheel) for a variety of things: cut, copy, paste, delete, return, escape, close tab.

Each assignment is a few lines of Autohotkey script.  I use LeftButton/ScrollDown for <ENTER>, maybe that sort of thing would work for you adjusted to the trackball.  A snippet of code I lifted/copied/adapted from someone/someplace else:

So a 1/4 acre is a ~52' square .

-Stoic Joker (February 04, 2013, 12:00 PM)

~104', it's a square